S07E19 - Night of the Rogues
Synopsis
Krang, Shredder, Bebop and Rocksteady break-in to the City Hall of Records and steal a file of maps of The City's sewer system dated 1895. Before they are able to escape back to the Technodrome, they get their collective butts kicked by the Turtles. Licking his wounds in the safety of the Technodrome, Shredder blames Bebop and Rocksteady for his failures, vows vengeance against the Turtles, and decides that while Krang begins his excavation project in the City's sewers (in hopes of discovering a source of treasure) he will be busy recruiting his new minions (to replace Bebop and Rocksteady who have been locked in a room to keep them out of harm's way) to help rid himself of the Turtles once and for all.
Concerned and confused by Krang's interest in the sewer system, the Turtles set out to investigate, only to quickly encounter Shredder and his villains and former foes, recruited to terminate the Turtles: the Rat King, Slash, Leatherhead, Temptesstra, Scumbug, Anthrax and Chrome Dome